Mining machine



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MINING MACHINE Filed March 21, 1934 14 Sheets-Sheet 1Q 'Q /N VEN TOR r Lew/s E M/7'c/7e BY ATT'Y Aug. 31, 1937. E. MITCHELL MINING MACHINE Filed March 21, 1934 14 Sheets-Sheet 11 1937- L. E. MITCHELL 2,091,413

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Aug. 31, 1937 L. E. MITCHELL 2,091,416-

MINING MACHINE Filed March 21, 1954 14 Sheets-Sheet 1-4 [N VENTOF? y L ew/S E/V/fcheM 7 BY Patented Aug. 31, 1937 UNH'EQ STATES PATENT @FFEQE MINING MACHINE ration of Ohio Application March 21,

15 Claims.

My invention relates to low vein, longwall, bottom kerf-cutting machines comprising a pivoted cutter bar adapting it to be used for either shortwall operations or longwall operations, and

one of the objects of my invention is the provision of improved and simplified construction for holding the Keri-cutting mechanism at an adjusted angle relative to the supporting frame of the machine.

Another object of, the invention is the provision of mechanism in this type of machine for swinging a pivoted cutter bar to a laterally extending position where the connection of such swinging means to the cutter bar remains accessible while the machine is at the coal face.

Another object of the invention is the provision of improved controlling and operating mechanism for fluid pressure means to adjust the elevation of the cutting mechanism.

A further object of the invention is the provision of an improved fluid pressure system for operating lifting skids of a mining machine which is adapted to slide on its own bottom over a mine bottom.

Another object of the invention is the provision of accessible manually operated thrust mechanism for operating a friction clutch for a rope drum in a mining machine, such manually operated mechanism being supported in stationary position while the drumv is rotated.

Another object of the invention is the provision of mechanism for operating a reversing switch of the motor of a mining machine in such a manner that a time element is introduced which will permit stopping of the motor before the electric connection thereto can be reversed.

A further object of the invention is the provision in a shortwall or longwall mining machine of emergency stopping mechanism operable from the cutting end of the machine without being able to re-start the operation of the machine from such cutting end of the machine.

Another object of the invention is the provision of a stepped guard for locking pins at the cutting end of the machine so that the machine may be useful for shortwall operations while such guard protects the locking pins and the steps of the guard are useful for releasing the pins.

Another object of the invention is the provision of improved means embodying toggle mechanism for operating the clutch and the power transmission mechanism connected to the kerf cutter so that the clutch will be held applied after the 55 actuating means is released,

1934, Serial No. 716,660

A further object of the invention is the provision in a mining machine which is adapted to slide over the mine floor during operation, of pipes extending through flame proof casing of an electric motor to enable cutting mechanism and operating means therefor to be placed at one end of said tubular casing and the controller means extending through said tubes to be located at the other end of said casing.

A further object of the invention is the provision of improved construction in hydraulic jacks connected to the frame work of a mining machine to adjust the elevation of the cutting mechanism thereof.

Another object of the invention is the provision of improved construction for enabling ready removal of a Worm gear along vertical lines from kart-cutting operating power transmission structure.

Another object of. the invention is the provision of an improvement in frame work of a mining machine to serve as a well for the fluid pressure medium in a fluid pressure controlling system without interfering with the lubricating enclosure for power transmission mechanism of a kerf cutter.

A further object of the invention is the provision of supporting bracket structure for detachably supporting friction sheaves, said bracket sup-port being mounted within the confines of the supporting frame work of the machine so as not to project therefrom while the machine is being used for longwall operations.

Further objects of the invention will appear hereinafter, the novel features and combinations being set forth in the appended claims.

In the accompanying drawings, 7

Fig. 1 represents a plan view of the mining machine embodying my improvement;

Fig. l is a section on the line l -I of Fig. 1;

Fig. 2 is an elevational view of the mining machine shown in Fig. 1;

Fig. 8 is an enlarged plan view of the cutting end of the machine with certain parts removed and others shown in section to facilitate illustration of controlling and operating mechanism;

Fig. 4 is a sectional elevational View approximately on the line i4 of Fig. 1 looking in the direction of the arrows;

Fig. 5 is a sectional elevational view taken on the line 55 of Fig. 3 looking in the direction of the arrows;

Fig. 6 is an enlarged plan view with certain parts removed and others shown in section, of

the haulage or front end of the machine shown at the right hand end of Fig. 1;

Fig. 6a is a view taken on the line (E -6 of Fig. 6;

Fig. 7 is a sectional elevation taken on the line ll of Fig. 6 looking in the direction of the arrows;

Fig. '7 is a View taken on the line li --11 of Fig. '7 looking in the direction of the arrows.

Fig. 8 is a sectional plan view taken on the line 88 of Fig. 7;

Fig. 9 is a sectional plan View of the auxiliary rope drum and the safety devices associated therewith;

Fig. 10 is a sectional elevational view of a portion of Fig. 9 taken on the line lfiit looking in the direction of the arrows;

Fig. 11 is an enlarged detailed View of a portion of Fig. 10;

Fig. 12 is an elevational View of the interior structure shown in section at the right hand portion of Fig. 7, the section being taken on line 52-42 of Fig. 6 looking in the direction of the arrows;

Fig. 13 is a sectional elevation taken on the section line l3 of Fig. 6 looking in the direction of the arrows, Fig. 13 being in elevation similar to Fig. 12 but omitting certain parts and adding others;

Fig. 14 is a sectional plan view taken on the line i i-44 of Fig. 13;

Fig. 15 is an enlarged sectional elevation taken on the line l5l5 of Fig. 6 looking in the direction of the arrows;

" Fig. 16 is a sectional elevation taken on the line i6i6 of Fig. 15 looking in the direction of the arrows; parts being broken away to show other parts;

Fig. 17 is an elevational view of one of the skids connected to the bottom of the mining machine;

Fig. 18 is an enlarged view of the means for detachably connecting one end of each of the skids to the bottom of the mining machine;

Fig. 19 is an enlarged sectional elevation of the hydraulic jack connected to the righthand end of the skid as viewed in Fig. 17;

Fig. 20 is a sectional elevation taken on the line Eii-Zfi of Fig. 3 looking in the direction of the arrows, and showing the pump mechanism for the hydraulic jacks connected to the skids;

ig. 21 is a diagrammatic View of the fluid pressure control system for the hydraulic jacks associated with the skids one of which is shown in elevation in Fig. 1'7;

Fig. 22 is a sectional View of the controlling valve of the system shown in Fig. 21;

Fig. 23 is an enlarged elevational view of a portion of the mechanism for operating the clutch for connecting the motor operated power transmission mechanism to the chain cutter; view taken on line 23-423 of Fig. 3;

Fig. 24 is an enlarged sectional plan View of a portion of the mechanism for operating the motor controller;

Fig. 25 is an enlarged sectional plan view of certain details of construction of the mechanism for operating the motor controller;

Fig. 26 is a wiring diagram of the electrical connections between the motor controller and.

the motor;

Fig. 27 is a sectional elevation showing the details of construction of the manually operated mechanism for actuating the motor controller;

Figs. 28, 29 and 30 represent diagrammatically shortwall operations of the improved mining machine;

Fig. 31 represents the arrangement of the ropes when the machine is permitted to slide of its own weight over the mine bottom toward the right;

Fig. 32 represents the position of the ropes when the machine is to be moved over the mine bottom by power after having been permitted to slide down an incline;

Fig. 33 represents the position of the haulage ropes when the machine is to be moved to a Working face preparatory to a cutting operation;

Figs. 34 and 35 represent longwall operations in opposite directions;

Fig. 36 represents a swinging kerf cutting movement into a longwall face;

Figs. 3'7, 38 and 39 represent diagrammatically the completion of a longwall cut at the end of a longwall face; and

Figs. 40 and il represent diagrammatically the haulage of the mining machine from its position where it has completed a longwall out,

By referring to Figs. 1 and 2, it will be seen that the supporting framework of the mining machine comprises an intermediate motor section iii, a front feeding and hauling section 44, and a rear cutting section 45. These sections are detachably connected together by means of stud screws as illustratedat 44' and 45 in Figs. 3 and 6. An elongated kerf cutter 28 projects from the rear end of the cutter-head section and is pivotally connected thereto. Releasable locking mechanism comprising vertical pins 31, ll is relied on to hold the kerf cutter in the position shown in Fig. 1 during the shortwall operations illustrated in Figs. 28, 29 and 30, or to hold the kerf cutter in laterally projecting positions for longwall operations illustrated in Figs. 34 to 39 inclusive. The elongated kerf cutter it? comprises elongated cutter bar 58 with a chain cutter 19 arranged to travel on the periphery thereof. The feeding and haulage section 44 comprises flexible draft elements which may be ropes as shown at 5% and 51 in Fig. 1, the free ends of which are adapted to be connected to fixed anchorages extraneous to the machine as illustrated in Figs. 28 to 41 inclusive.

Each of the sections 43, 44 and 45 is self-contained and when bolted together the overall height of the machine is no greater than the distance between the horizontal planes extending through the upper and lower surfaces of the motor section 43. The machine is therefore well adapted for the cutting of kerfs in relatively low veins and the construction hereinafter described permits the use of a relatively high horse power electric motor and the use of operating and controlling apparatus within the space between such upper and lower horizontal planes while at the same time keeping the width and length of the supporting framework within such limits as is consistent with the free sliding of the machine on its own bottom over the mine bottom along narrow passageways between timbering and the upright coal faces and other places in the mine where the available spaces are very limited.

The bolting together of the various sections 43, M and 45 is such that the sections may be readily separated at the coal face where the roof in the entry or room is only slightly higher than the top of the machine itself. This is an advantage when repairs and replacements are desired to be made adjacent to the coal face; for instance, the armature and field coils of the electric motor may lit be replaced and the sections reassembled adjacent to the coal face to place the machine in condition for further operations.

In Fig. 3 the electric motor armature 52 is shown provided with a shaft 53 journaled in the ball bearing 54 and having secured at the right end thereof a pinion 55 which meshes with a gear 55. The latter is keyed to the left hand end of the shaft 5'! journaled in the bearings 5'! and 5 mounted in the frame of the cutter-head section 45.

The shaft 51 carries a worm 5B which meshes with a worm wheel 59- rotatable on a vertical axis approximately midway between the sides of the machine. The worm wheel 59 as shown in Fig. 5 is secured to a hub 60 mounted loosely on the bushing 6! which surrounds the vertical shaft 62.

The vertical shaft 62 is j ournaled to rotate between the top conical thrust bearing 63 and the bottom conical thrust bearing 64 between the cover plate 65 and the bottom casting 99 of the box-like enclosure having the end wall plates 61 and 68.

As shown in Fig. 1 the cover plate 65 may be secured by means of bolts 69 to the vertical wall plates of the box-like enclosure shown in Fig. 5.

By means of a transverse partition iii the interior chamber ii is provided for containing lubricating oil which may be introduced through the opening at 12.

An auxiliary cover plate 13 is detachably secured by means of the cap screws M to the ring shaped support 15 which depends from the cover plate 65 and may be integral therewith as shown in Fig. 5. The inner surface of the support 15 is cylindrical to receive the outer roller bearing race 15, the inner race l1 being secured to the upper end of the shaft 62. A cap plate it? kept from rotating relatively to the shaft 62 by means of the pin T9, may be secured in place by means of the screw as shown in Fig. 5 so as to hold the inner race H in place.

When the auxiliary cover plate 13 is removed the chamber 8! may be filled with lubricant for the upper thrust roller bearing. The worm gearing 58, 59 and the parts below the same may be lubricated by introducing lubricant through the oil opening l2 in the main cover plate as shown in Fig. 5. Preferably the oil introduced into the chamber H should be at such a level as to submerge only the lower portion of the gear 59 so that when the machine is on steep grades the oil in chamber M will not drain over into the hydraulic pump compartment hereinafter described.

Intermediate the ends of the shaft 62 is welded, as indicated at 82 in Fig. 5, a cup shaped support 83 which carries on its outer surface a plurality of circumferentially spaced vertical splines 84 which drive the vertically slidable clutch element The lower portion 86 of the clutch element is cylindrical in shape and provided with an annular shoulder 8'! against which is held the clutch lifting ring or yoke 89. A series of circumferential oblong openings 9! is provided to reduce the weight of metal, as clearly shown in Figs. 3 and 5. The yoke 89 is held in place by means of a collar 88 secured to the lower end of the member 85 by means of shoulder pins. The movement of the clutch yoke 89 up or down carries the clutch element 85 into or out of engagement with the clutch element 94. It should be understood that when the cover plate 85 is removed the worm gear 535i and the cup shaped support 83 may be removed and then when the shoulder pins are released the lower clutch element 85 may be also released from the yoke 89.

Riveted to the under side of the hub 60 as indicated at 92 is a ring 93 the under side of which is provided with a series of clutch teeth 96. It should be understood that the hub 60 always rotates with the worm gear 59 and that the cup shaped support 83 always rotates with the vertical shaft 62. The upper side of the clutch element 85 is provided with clutch teeth adapted to engage the upper clutch teeth 94.

At diametrically opposite sides of the disc shaped yoke 89-, 9!) are trunnions 95, 95 to which are journaled the arms 96, 96 pivoted at 971', 9? to brackets the lower ends of which are screwthreaded at 98, 98 to the bottom 99 of the boxlike enclosure.

The bottom 99- of the cutter-head section 45 is provided with a recess at Hill for the lower roller bearing M and immediately above this recess but of larger diameter is another recess it! to receive the means comprising the cork ring lill for providing an oil seal to prevent loss of lubricant from the bottom of the chamber H. The oil seal at Hi3 below the roller bearing 64 and immediately above the chain driving sprocket Hi l is provided for the purpose of preventing dirt or foreign matter from entering the lower side of the roller bearing 64.

It will thus be seen that all of the bearings in the cutter-head section &5 are well lubricated, the gear drives being placed in an oil-tight gear housing which has a removable top cover plate 65 so that the gears may become readily accessible for replacement or repairs.

Although the chain driving sprocket ltd is shown riveted at one of the rivet heads may be removed and the rivet detached so that when the sprocket Hid is removed the shaft 62 together with the hub 56 and worm gear 59 may be taken out of the housing after the cover t5 has been detached. When the shaft 62 is lifted out, the inner race of the lower roller bearing and the cup shaped support 83 may be also removed. On account of the curvature of the teeth of the Worm gear 59 the caps for the ball bearings El and L l shown in Fig. 3 should first be detached so as to free the worm 58 from such curvature. When the worm gear 59 is lifted out, the lower clutch element 85 remains connected to the clutch yoke 89. The pins holding the collar 83 in place cannot be withdrawn until the cup-shaped support 83 has been lifted out of the clutch element 85. The pins may then be pressed inwardly to release the collar 88, whereupon the clutch element 85 may be removed.

The kerf cutter it shown in Figs. 1 and 2 comprises a cutter bar 48 which is so supported. on the cutter-head section 65 so that the lower plane of the kerf cut by the kerf cutter will be flush or substantially flush with the bottom of the machine. That is to say, the lower plane of the kerf to be out should be in continuation of the plane of the mine bottom.

The cutter head mounting has the form of a circular turntable it! which is provided with an overhanging bracket M8 to which the cutter bar support 48 is rigidly secured by any desirable securing means such as the welding till shown in Fig. 5.

As shown in Figs. 4 and 5 the lower surface tilt of the wearing shoe 38' which is secured to the cutter-bar support 48' by the cap screws I65, is adapted to slide over the mine bottom during cutting operations. It should be understood that when the cutter bar support 48 is mounted as shown in Fig. it is rigidly connected to the turntable Hill to extend radially therefrom and rotate bodily therewith.

The central portion of the turntable IIl'I is pro- 5 vided with a cylindrical hub III? which is journaled on the outer cylindrical surface of the depending cup shaped portion 65 of the bottom casting 99.

A circular plate I II is welded to the bottom of the casting 99 to form part of the annular groove I I2 into which are fitted two semi-circular plates H3. By means of a series of circumferentially spaced screws I It the semi-circular plates I I3 are rigidly attached to the upper peripheral circular portion of the turntable Ili'l. The turntable is thus suspended from the bottom of the casting 99 by means of the semi circular plates I it fitting in the groove II2.

When it is desired to remove the cutter head or rotatable turntable Iil'I together with the cutter bar rigidly attached thereto, the screws II I may be removed to release the semi-circular plates I I3. Some of the screws IM may be released by removing the screw plug II5 shown at the left hand portion of Fig. 5. This may be done after removing the cover plate H6 which is detachably mounted as shown in Fig. 1 by means of the bolts or screws Ill. The removal of the cover plate 5 I6 also renders accessible the mechanisrn located in the compartments containing the pumping apparatus and the inter-meshing gears 55 and 5G.

The mechanism for applying and releasing the clutch shown in Fig. 5 for connecting the worm wheel 59 to the chain driving sprocket ili l, is operable from the front end of the machine where the haulage and feeding section 45 is located. As shown in Fig. 3 a cross-piece IIS connects the ends of the arms 9% remote from the trunnions 95. At the center of the cross-piece H8 is an arm II9 to which is screw-threaded a pivot block E20 as shown in Fig. 23.

A stationary bracket IEI is mounted on a support I22 which is secured to the bottom wall 99 of the chamber ll as indicated at 222' in Fig. 23. Toggle mechanism comprising the links I23, I24 and I25 is connected between the pivot block 520 and the upper end of the bracket I2 I. When the link H5 is pulled toward the left as viewed in Fig. 23 the pivot block I'Zt is pushed down and therefore the trunnions 95 shown in Fig. 3 are lifted and this operation effects throwing in of the clutch comprising the elements 85 and S l The left hand end of the link I25 is pivoted at 629 to the link I39 the lower end of which is pivoted at ISI to the bracket H22, and the upper end of which is pivoted at I32 to the pivot block into which is screw-threaded an operating rod Kit. The forward end of the operating rod 60 I36 is mounted in a slide bearing as shown in and the end of the rod is provided with a cross-piece or hub I3=3 which engages the front face of the bearing I so as to limit the movement of the rod I3 3 rearwardly or toward the 5 right as viewed in Fig. 24. The cross-pin I38 supports the handle I3? which may be lifted to a horizontal position as shown in dotted lines at It? in Fig. 24 and then grasped to pull the rod 55M and thereby move the link E25 to the left as 0 viewed in Fig. 23. The pulling out of the handle I3? pushes dovm the arm I I9 shown in Fig. 3 and consequently the trunnions 95 are lifted and the clutch is applied to connect the worm gear 58 to the vertical shaft 62 and the chain driving 75 sprocket IM. A coil spring I26 is supported on studs I21 and. I28 on bracket I2I and link I30, respectively.

The spring I26 is a compression spring and therefore assists in applying the clutch but the pivot I38 does not move into a straight line extending through the pivots I39 and I48 but remains to the right thereof as viewed in Fig. 23. The spring and the toggle mechanism are therefore able to easily hold the clutch applied when the handle IE7 is released. When it is desired to release the clutch the rod I34 must be pushed back to its full line position shown in Fig. 24 and this operation will effect a positive movement of the link I25 to its position shown in Fig. 23 whereupon the arm IIEl shown in Fig. 3 Will be positively lifted and the clutch elements 85 and 53, M will be released by a direct force exerted by the attendant when he grasps the handle I3? and pushes the rod ltd rearwardly back to its position shown in Fig. 24. It will thus be seen that the spring I26 in its tendency to apply the clutch counterbalances the weight of the clutch element 85 and the ring 89 tending to release the clutch, thereby greatly facilitating the manual operation of the clutch in applying and releasing the same.

Referring now to the haulage and feeding sec tion id of the machine, it will be seen that the forward end of the armature shaft of the electric motor 52 is coupled to a shaft I lI journaled in ball bearings and secured to the worm M2 which meshes with a worm wheel I43 journaled on the vertical shaft hi6. By means of three bolts M5 an eccentric cam MES is rigidly secured to the hub portion I41 of the worm gear I43. The worm gear M3 and the eccentric cam I45 are respectively mounted on spaced ball bearings I 38 and I 59 for free rotation relatively to the vertical shaft M4. When the motor operates to rotate the worm I42 rotary motion is imparted through the worm gear I63 to the eccentric cam It? to rotate the latter freely on the ball bearings M8, I49 relatively to the vertical shaft I.

When the eccentric cam M6 rotates it engages a circular ring I 50 which is mounted by means of the roller bearings I5I for free rotation on the vertical bearing I 52, as shown in Figs. 6 and '7.

The ring roller I59 and the vertical bearing I52 are carried on the bell crank leve I53 as shown in Fig. 6. This bell crank lever is pivoted at I5 where it is supported by the frame I55 for oscillation on a fixed vertical axis.

To that end of the bell crank lever I53 remote from its pivot I54, is pivoted at I56 a screw rod I57 which is adjustably connected to the screw-threaded block I58, the latter being pivoted at I533 to the oscillating pawl carrier Hit.

By referring to Fig. 7, it will be seen that the pawl carrier Iiid is provided with a central cir cular portion which is journaled on the hub IliI of the ratchet wheel I52, the latter being keyed indicated at I63 to the upper end portion of the vertical shaft M4. The pawl carrier Iliil may be locked in place as shown in Fig. '7 by means of the cylindrical bracket I54 suspended from the bottom of the plate I65 which is secured by bolts I61 to the box-like structure comprising the vertical plates 568.

The cover plate I66 may be fastened to the plate I535 by the machine screws Hit", there being apertures in the plate I65 that may fit over the heads of bolts IIi'I as shown in Fig. l.

A central circular cover plate I 68 may be connected by means of the screws I'Iil as shown in Fig. 1, to the central portion of the plate H55. When the plate I59 is removed access may be had to the chamber ill to lubricate the ball bearings H2 which fit in the cylindrical recess in the bracket I6 3. The ball bearings H2 afford a means of journaling the upper end of the vertical shaft M4 in the bracket Mi l.

When the cover plate E65 is removed access may be had to the chamber H3 and the mechanism therein. It should be understood that the chamber H3, when all the parts are assenibled and when the covers are attached, affords a closed lubricating chamber for the worm gear-- ing and the ratchet feeding mechanism, all of the parts shown in Fig. '7 in the chamber H3 running in oil.

Pivoted at lit to the pawl carrier lei? is a spring pressed pawl H5 in position to engage the teeth of the ratchet wheel l62. It will thus be seen that when the cam it is rotated, the bell crank lever L53 will be oscillated and the pawl and ratchet mechanism will be intermittently actuated to efiect a step by step feeding movement of the vertical shaft M6 in an anticlockwise direction as viewed in Fig. 6. A spring pressed retaining pawl H5 is pivotally mounted on the axis for movement independently of the bell crank lever let and in position to engage the ratchet teeth to prevent retrograde movement of the vertical shaft HM. By means of the adjustment which may be effected between the members 551 and I58 the pawl. H5 may be adjusted so as to enter properly the notch between the ratchet teeth when the roller i529 is nearest the vertical shaft Md.

The rotation of the cam MB thrusts the roller E58 outwardly away from the shaft Md and thereby causes a forward anti-clockwise movement of the pawl H5 together with the ratchet wheel 5E2. In order to return the pawl M5 to its initial position a restoring spring shown at ill in Figs. 6 and 15 is relied upon. This spring is located in the tube H3 between the transverse partition H9 and the head iiifl which is pivotally connected at lti to the link E82 the other end of which is pivoted at 83 to the bell crank lever I53. (See Fig. 15.)

The restoring movement or return throw of the pawl H5 may be varied or regulated in accordance with the extent of feed desired. A rod 184 which is pivotally connected at one end to the head I89, slides through the center of the partition H9 and is connected at its outer end to the stop I85. It will thus be seen that the spring I'll can move the pawl H5 in a clockwise direction as viewed in Fig. 6 only to the extent permitted by the stop H35 striking against the partition H9.

The position of the partition H5 may be varied by sliding the tube H8 in the cylindrical or tubular support l86 which is detachably secured to the plate lt'i, the latter being in turn detachably secured to the supporting framework of the machine.

Mounted in the cap bearing 38 is an adjust ing screw I35 capable of rotary but not endwise movement. When the manually operable wheel lfifi is rotated the screw H89 is rotated and since this screw is screw-threaded through the left hand end of the tube I13, as viewed in Fig. 6, the partition H9 will be moved to varied distances from the shaft M4.

As shown in Figs. 6, 15 and 16 a collar l9! fits in the cap bearing I88 for rotary movement and is provided with a notch H22 in which is adapted to fit a ball 5% urged by the spring pressed cup l9 l into the notch. The compression of the spring I may be regulated by the screw plug it.

The pitch of the screw-threads W9 is such that when the wheel I95 is given one rotation so that the ball Hit may be reseated in the notch H72, the partition H9 will be moved such a distance as to cause the pawl lit to be reset to a position one notch from its previously adjusted position. For instance, the adjustment of the partition H9 may be such as to cause the pawl lid to remain in a certain notch even though the cam M5 is rotated, thereby effecting no feed at all. Adjustments may also be made to cause the pawl M5 to move the ratchet Wheel either one notch, two notches, three notches, or four notches, as may be desired. Full speed feeding transmission mechanism may thus be effected for pur poses hereinafter more fully explained. It should be particularly noted, however, that all feeding movements or step by step advances of the ratchet wheel l62 are unidirectional irrespective of the direction of rotation of the armature shaft. That is to say, it is immaterial whether the motor is rotating in one direction or in a reverse direction. The rotation of the cam it will always cause oscillation of the bell crank I53 so that the reciprocation of the pawl ill? will always be the same and the rotation of the shaft M l as viewed in Fig. 6 will always be in an anti-clockwise direction.

At the lower end of the vertical shaft M l as shown in Fig. l is a pinion l9? which meshes with a gear its journaled by means of the ball bearings its to the vertical bearing 2% extending upwardly from the bottom plate 2% of the sup porting frame of the haulage and feeding section A l. The gear E98 meshes with the relatively larger gear 292 which is keyed at 263 to the cylindrical hub 254 to the upper end of which is connected one element 2535 of a friction clutch 20%, the other element 25'? of which is located on the interior of the rope drum 2%. The bushing 209 is pressed into the sleeve 2% for journaling on the: vertical stationary bearing 2 iii, the latter being secured to the top plate 236 by being keyed thereto as shown in Fig. 7.

As shown in Fig. 8 the gear 282 meshes with a gear 21 l mounted to rotate about vertical bearing 2l2 which is similar to the vertical bearing 2H0. Also mounted to rotate about the vertical axis of the bearing 252 is a rope drum 2H, and between the gear 2H and the rope drum M3 is a sleeve friction clutch and rope drum similar in all respects to the structure shown at the left hand portion of Fig. '7. The gear 262 rotates in an anti-clockwise direction as viewed in plan and the gear 2 rotates in a clockwise direction and the ratio between these gears. is such that the gear 2 will rotate approximately ten percent faster than the gear 202 for the purposes hereinafter explained.

As shown in Fig. 7 the hub 2 it is provided with a cup-shaped bearing El i which is held against rotation relative to the bottom plate Zill by means of the pin H5. The hub Zlt of the large spur gear 262 rests on the bearing plate 2M within the cylindrical flange 25! which affords an oil cup. This hub 2ft carries the portion 264 of the clutch element 205.- The upper end of the hub 216 is. provided with a ring packing 2E8 which bears against the inner surface of the stationary ring 2l9 to form a dirt seal, the ring 269 being mounted in a circular opening in the cover plate 220. This cover plate may be provided with the extension 22! for the space in which the spur gear 27! rotates. A vertical extension may also be provided at 222 (Fig. '7) and suitable partitions provided as shown'at 223, 224 and 225 to cooperate with the cover plate 220, 22! to provide an enclosure for the spur gearing shown in plan in Fig. 8.

A star-shaped plate 226 (Figs. 7 and 7 is connected by means of the pins 226 to the hub 276 to rotate therewith and to make a close sliding fit with the upper surface of the cover plate 220. The star plate 226 acts to throw out coal dust or foreign material from under the rope drum 208 to keep such material from entering the chamber below the plate 220 and to prevent such material from retarding free rotation of the rope drum 208. A similar star plate is located under drum 273.

By providing a floor 227 for the chamber I73 as shown in Fig. 7, a separate closed chamber 228 may be provided for the spur gearing. The central portion of the floor plate 227 may also aiford support for the outer race of the ball bearing 230. Suitable lubricating means may be provided for the spur gearing in the closed chamber 228.

Connected to and Wound on the rope drum 208 is a rope 50 the free end of which is adapted to be connected to a fixed anchorage in the mine extraneous to the machine as illustrated in the diagrammatic views, Figs. 28 to 41 inclusive. Connected to and wound on the rope drum 2|3 is a rope 5! the free end of which is also adapted to be connected to a fixed anchorage in the mine. The application of power transmitted from the motor to each rope drum is controlled by the friction clutch associated therewith. As above stated, each of the rope drums 208 and 273 is provided with its own friction clutch and each friction clutch is operated by the mechanism shown in Fig. '7.

A transverse top plate 234 is securely bolted to the side walls of the frame of the section 43 and the upper ends of the vertical cylindrical bearings 2H0 and 212 are secured thereto so as to prevent rotation of said vertical bearings relative to the supporting frame of the machine. Beneath the plate 234 and keyed to the stationary bearing 21s at 235 is a screw-threaded bushing 236 which is provided in its lower inner side with a seat 237 for a ball bearing 238. It will thus be seen that the sleeve 204 is mounted so that it will have no vertical movement relative to the bearing 2H0 but may rotate with the bushing 209 while provided with the thrust bearing 238 at its upper end.

Journaled on the bushing 239 surrounding the sleeve 204 is a sleeve-shaped hub 240 at the interior of the rope drum 208. The rope drum is therefore mounted for rotation on the sleeve 200 and the latter in turn is mounted for rotation about the vertical axis of the bearing 2 l0.

Mounted at the upper side of the drum 203 as shown at 2M is the outer race 242 of a ball bearing 243 the inner race 244 of which is riveted as shown at 245 to the wheel 246 screwthreaded on to the screw-threaded bushing 236.

Radial spokes or handles 247 on the wheel 246, some of which handles always project out from beyond the plate 234, may be used to turn the wheel 246 on the screw 236 to lift or lower the ball bearing 243. This ball bearing supports the rope drum and also the clutch member 207. Therefore, when the ball bearing 243 is lifted the clutch is applied to direct transmission of power from the spur gear 202 to the flexible draft element or rope 50. In a similar manner transmission of power from the spur gear 2 to the rope drum connected thereto may be effected by grasping the radial handles 247' and turning the wheel 240 to obtain a pull on the rope 5|. As shown in Fig. 6, when the two rope drums are rotated in opposite directions and each unidirectionally, pulls will be exerted on both of the ropes 50 and 5|.

As shown in Figs. 1, 2 and 6 rope directional sheaves may be located at various corners of the machine. The directional sheaves may be superimposed as shown at the right hand end of Fig. 2, the wider sheave 232 being used for a rope extending directly from the rope drum, and the upper sheave 233 being used when the rope 50 is directed around the same. One directional sheave 200 is sufiicient for the rope drum connected to the larger spur gear 202. These directional sheaves are shown in sectional elevation in Fig. 1

At the rear end of the machine a directional sheave 249 may be mounted on an arm 250 which is detachably connected at 250 to 2. depending bracket 252 or to a depending bracket 252 at either corner on opposite sides of the machine, as shown in Fig. 4. During longwall operations the brackets remain within the confines of the supporting framework.

In order to slide the machine over the mine bottom at a relatively fast or haulage speed, mechanism is provided as shown in Figs. '7 and 10 to 14 inclusive, for connecting the worm wheel M3 directly to the shaft M4 and the pinion I97 to drive the latter independently of the pawl and ratchet feeding mechanism shown in Fig. 6. By means of the handle 253 connected to the rock shaft 250 which is journaled on the bearing 255, the slotted disc 256 may be moved from the position shown in Fig. 13 to a clutch applying position and held there after the handle 253 is released.

In the slot 257 of the disc 256 is pivoted at 258 the upper end of a rod 259 the lower end of which is provided with a nut 200 engaging the lower end of the compression spring 26L the latter being mounted in a tube 202 the lower end of which is connected to the L-shaped member 263 secured to the arm 264. The other end of the arm 200 as shown in Fig. 14 is secured to a tube 265 journaled on a bearing rod 266 mounted in the brackets 207 and 238. Secured to the other end of the tube 250 is another arm 269. Trunnions 270, 270 carrying a ring 27!, are journaled in bearings at the outer ends of the arms 264 and 289 as shown in Fig. 14.

Carried by the ring 27! is a lower clutch element 272 winch is provided with beveled clutch teeth 272' adapted to engage the upper clutch element 273 secured to the lower side of the worm gear M3 as shown in Figs. '7 and 13. The lower clutch element 272 is disc-shaped and its periphery fits in an inner annular groove of the ring 27!. The latter may be constructed of semi-circular parts'bolted together as shown at 274, 274 in Fig. 14 to clamp the ring 2' to the clutch element 272.

It should be particularly noted that the interior meshing teeth 272 and 273 are provided with such beveled surfaces that when the worm gear M3 is rotated in a clockwise direction as viewed in plan, the clutch 272, 273 will be in- 

